ACANTHONOTOZOMATIDAE 117 



The three species of Echiniphimedia are omitted from the above list ; Acanthonotozo- 

 mella alata, Schell., has only medio-dorsal carinal teeth. 



Another point which needs investigation is the imbrication of the lower margins of 

 the peraeon segments over the bases of the respective side-plates, and the consequent 

 formation of a lateral keel. Is this primary or secondary armature; is it specific or 

 varietal ? 



Genus Acanthonotozomella, Schell. 



Schellenberg, 1926, p. 332. 

 Barnard, 1930, p. 346. 



Acanthonotozomella oatesi, Brnrd. (Fig. 65). 

 Barnard, 1930, p. 346, figs. 20, 21. 



Occurrence: 1. St. 39. South Georgia. 1 c? 9 mm. 



2. St. 144. South Georgia. 1 $ 7 mm. 



3. St. 156. South Georgia. 1 c? 7 mm - 



4. St. 190. Palmer Archipelago (90-130 m.). 1 rj 6-5 mm. 



5. St. WS 33. South Georgia. 1 9 with embryos 9 mm. 



Remarks. Whereas the specimens from St. 156 and 190 (the latter from a locality 

 nearest to the original locality) are nearly 

 typical examples, the others show some 

 noteworthy variations. Even in those 

 from St. 156 and 190, the 1st peraeon 

 segment is slightly broader than in the 

 Terra Nova specimens, and the dorsal 



processes have broader bases, occupying 



.1 11 . . r .1 . t .1 Fig. 6?. Acanthonotozomella oatesi, Brnrd. a. Head of 



the whole extent of the segment. In the ° 3 ' 



. °. from St. 144. b. Cross-section of peraeon segment 3 



other specimens the 1st segment is dor- of ^ from St 



sally lengthened, and the two processes 



are confluent in front, divergent behind, and thus enclose a concave space which when 



seen from above is triangular in shape. This development is most marked in no. 2 



(Fig. 65 a). All the dorsal processes appear to have a tendency to vary in length. Those 



on peraeon segments 2-4 are often distinctly shorter and more slender than in typical 



examples; and in no. 1 they are absent altogether, these three segments having merely 



a transverse ridge on the hind margin, with squarish corners when seen in cross-section 



(Fig- 65 b). 



The embryos from the brood-pouch, 2-5 mm. in length, possess no spiny armature, 

 except a pair of short adpressed dorsal processes on peraeon segment 7 and pleon 

 segments 1-4. 



The label of no. 3 says, "with the Gastropod in which it was found". The mollusc 

 with its operculum, however, is still in the shell, so that the presence of the Amphipod 

 in the mouth of the shell can only be regarded as accidental. 



Distribution. Ross Sea, 82-92 m. 



